The invention relates generally to three-phase converters for polyphase induction motors, and in particular to such an converter with an input transformer that has at least two secondary windings associated with each primary winding, and has controlled power semiconductors.
Various versions of three-phase converters with an input transformer and controlled power semiconductors are known. B.R. Pelly, Thyristor Phase-Controlled Converters and Cycloconverters, WILEY-INTERSCIENCE, a division of John Wiley & Sons, Inc., NY, London, Sydney, and Toronto analyzes these converter determining their advantages and drawbacks. This book describes the Symmetrical Six-Pulse Midpoint Circuit on page 210 and illustrated it in detail on page 211. This converter is complex, large and relatively inefficient.
The present invention is directed to solving the problem of developing a (2.times.3)-pulse converter, that is simpler, smaller, and more efficient than the prior art.